YARN-4246. NPE while listing app attempt. (Nijel S F via rohithsharmaks)

(cherry picked from commit b57f08c0d2dae57b545a3baa213e18464060ae3b)

hadoop-yarn-project/CHANGES.txt

@@ -945,6 +945,8 @@ Release 2.8.0 - UNRELEASED
 
     YARN-3724. Use POSIX nftw(3) instead of fts(3) (Alan Burlison via aw)
 
+    YARN-4246. NPE while listing app attempt. (Nijel S F via rohithsharmaks)
+
 Release 2.7.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/cli/ApplicationCLI.java

@@ -349,8 +349,9 @@ public class ApplicationCLI extends YarnCLI {
       appAttemptReportStr.println(appAttemptReport
           .getYarnApplicationAttemptState());
       appAttemptReportStr.print("\tAMContainer : ");
-      appAttemptReportStr.println(appAttemptReport.getAMContainerId()
-          .toString());
+      appAttemptReportStr
+          .println(appAttemptReport.getAMContainerId() == null ? "N/A"
+              : appAttemptReport.getAMContainerId().toString());
       appAttemptReportStr.print("\tTracking-URL : ");
       appAttemptReportStr.println(appAttemptReport.getTrackingUrl());
       appAttemptReportStr.print("\tRPC Port : ");
@@ -667,6 +668,7 @@ public class ApplicationCLI extends YarnCLI {
       writer.printf(APPLICATION_ATTEMPTS_PATTERN, appAttemptReport
           .getApplicationAttemptId(), appAttemptReport
           .getYarnApplicationAttemptState(), appAttemptReport
+          .getAMContainerId() == null ? "N/A" : appAttemptReport
           .getAMContainerId().toString(), appAttemptReport.getTrackingUrl());
     }
     writer.flush();

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/test/java/org/apache/hadoop/yarn/client/cli/TestYarnCLI.java

@@ -1590,4 +1590,27 @@ public class TestYarnCLI {
   private static String normalize(String s) {
     return SPACES_PATTERN.matcher(s).replaceAll(" "); // single space
   }
+
+  @Test
+  public void testAppAttemptReportWhileContainerIsNotAssigned()
+      throws Exception {
+    ApplicationCLI cli = createAndGetAppCLI();
+    ApplicationId applicationId = ApplicationId.newInstance(1234, 5);
+    ApplicationAttemptId attemptId =
+        ApplicationAttemptId.newInstance(applicationId, 1);
+    ApplicationAttemptReport attemptReport =
+        ApplicationAttemptReport.newInstance(attemptId, "host", 124, "url",
+            "oUrl", "diagnostics", YarnApplicationAttemptState.SCHEDULED, null,
+            1000l, 2000l);
+    when(client.getApplicationAttemptReport(any(ApplicationAttemptId.class)))
+        .thenReturn(attemptReport);
+    int result =
+        cli.run(new String[] { "applicationattempt", "-status",
+            attemptId.toString() });
+    assertEquals(0, result);
+    result =
+        cli.run(new String[] { "applicationattempt", "-list",
+            applicationId.toString() });
+    assertEquals(0, result);
+  }
 }